> When you mark a page UCWC, you better
> have removed all cached mappings or your asking for REAL trouble.
What exactly do you mean by "removed all cached mappings"? Does that mean that
if one virtual address is a UCWC mapping of a physical page, then ALL virtual
addresses mapped to that page must also be UCWC?
In my driver, I use ioremap_nocache() on physical memory (real RAM) to create
an uncached "alias" (a virtual address) to a physical page of RAM. When I
access the memory via this virtual address, the memory access is not cached.
What I reall need is to be able to also have that virtual address as Write
Combined.
Since all physical RAM is mapped as cached via the kernel (on a 1-to-1 basis),
and since there can be several other virtual addresses that point to that memory
(e.g. user virtual address), I can't see how these virtual addresses can be
removed.
-- Timur Tabi - ttabi@interactivesi.com Interactive Silicon - http://www.interactivesi.comWhen replying to a mailing-list message, please direct the reply to the mailing list only. Don't send another copy to me. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/